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Alen a350 Air Purifier Review

Last updated July 16, 2021

This post may contain affiliate links.

Author avatar Danny Ashton

Danny as been writing about air purifiers for 10+ years. He is a major fan of home technology, which makes him the perfect person to test and evaluate products for HouseFresh

Updated 2020

The Alen A350 was an air purifier that was first sold in 2010, if you already have one of these units then congrats on keeping your unit running for 10 years. You will also be happy to know that you can still buy filters for these units:

Alen BF25A-Silver Filter, True HEPA Silver
  • Silver-Ion Technology protects the filter against growth of harmful bacteria and microbes
  • Creates an allergy and asthma friendly environment by removing dust, pet dander, mold spores and pollen from the air
  • Provides pure, breathable air by capturing VOCs (Volatile Organic Compounds) from cleaning products, personal care items and other household materials
  • Pre-Filter layer extends the life of the filter

Sadly the Alen A350 is no longer for sale but there are a number of new Alen units that you might be in interested in that have a similar specification:

1. Alen BreatheSmart Flex

Alen BreatheSmart FLEX Air Purifier, Medical Grade Filtration H13 True HEPA for 700 Sqft, 99.99% Airborne Particle Removal, Captures Allergens, Bacteria, Germs, Mold, Odors from Smoke, in White
  • RECOMMENDED FOR: Dust, allergens, pollen, fur, pet dander, household odors PLUS smoke from cigarettes, wildfires, and VOC fumes from chemicals and aerosol sprays. Sleek design fits in any space from small to large rooms.
  • B4-FRESH FILTER: Has 0.66 lbs of activated carbon to absorb smoke and toxic smells to help prevent respiratory issues.
  • TRUE HEPA: Includes a Medical Grade H13 True HEPA layer that removes 99.99% bacteria, aerosolized viruses, and airborne particles larger than 0.1 micron. True HEPA filters last 3-5 months longer than standard filters.
  • CLEANS AIR FAST: Cleans 700 SqFt every 30 minutes, twice as fast as key competitors on Turbo speed. Perfect for any space from small to extra large bedrooms, living rooms, offices, nurseries, kitchens, and basements.
  • SLEEP MODE: Features a “lights out mode”, press the power button once and the lights turn off. SleepScore validated and users feel more rested upon waking. rested the morning.

With a CADR rating of 230 for pollen, the breathsmart flex would be the A350 for the modern era. This unit comes with the same Alen lifetime guarantee so you can expect this air purifier to keep performing beyond 2030!

2. Alen BreatheSmart T500 

Alen T500 True HEPA Air Purifier, Allergies + Germs & Mold, White
  • RECOMMENDED FOR: Dust, dander, allergens, pet fur, odors and cleans up to 500 SqFt of air every 30 minutes on high speed
  • TRUE HEPA FILTER: Includes a Medical Grade H13 True HEPA layer that captures 99.99% bacteria, aerosolized viruses, and airborne particles larger than 0.1 micron AND includes a vacuumable pre-filter to help increase filter life
  • ANY ROOM SIZE: Fits perfect in any space from small to large rooms, living rooms, bedrooms, dorms, offices, bathrooms, nurseries, and kitchens
  • SIMPLE TO USE: Quickly adjust settings with a touch of a button
  • CERTIFIED: Energy Star Certified and Certified Ozone Safe by the California Air Resources Board (CARB)

This unit is a little cheaper but still has a CADR rating for dust of 159 so less powerful than the A350 but can often be found for less than $250 so significantly cheaper. This is a low priced unit but still comes with the Alen lifetime guarantee. This unit comes with the H13 which are the same filters used for medical grade air purifiers.

The following article is our original review of the Alen A350 Air Purifier from 2010:Alen a350 Air Purifier 

PRICE = $399 (

Before we start to dig deep into the pros and cons of this particular purifier. It’s worth having a look at what consumers at the major retailers think of this purifier. Most large internet retailers allow consumers the ability to provide a rating for their purchase. I use this rating as an initial way to quickly gauge the performance of an air purifier.

Review SiteRating
Amazon.com4 Stars (30 reviews)
Epinions.com5 Stars (8 reviews)
Wize.com4.5 Stars (77 reviews)
Shopping.com4.5 Stars (8 reviews)
Air Purifiers America4.5 out of 119 (10 user reviews)

The Alen a350 purifier has achieved favourable scores across a wide range of sites. I

Note: Air Purifiers America has business connections to Alen so we need to take their scores less seriously than the other more independent retailers.

The video below will take you through a sample of reviews so you can get an idea of what people like/dislike about it:

The next step we take for this air purifier review is to dig a little deeper into what the experts are saying about this purifier:

1. Air Purifier Power – Written By Ed Sherbenou – URL


Air-Purifier-Power Rating: 82, good


  • In recent assessments by this A-350 eliminated 98% of the contaminants in the device and 97% of the contaminants within the room.
  • The A 350 purifier is great at airborne dirt and dust and plant pollen elimination, yet is also competitively cost-effective costing under $300..
  • So the projected CADR (for basic comparability to mid priced store bought models without having chemical substance blocking capability ) is 203.
  • The manufacturer guarantees 95% of purchases are going to be delivered within Twenty four hours, and also features a straight forward return policy.


  • Significant gas and smell elimination is really a necessity if health benefits can be envisioned: Models with actual carbon VOC ability position higher.
  • Alen A350 air purifier sound amounts will be over normal: 36 decibels(A)on low setting, 65 decibels(A)@214cfm on highest setting. 65 decibels(A) isn’t the loudest, but 214cfm is fairly weak for that amount of noise.
  • The organization doesn’t sell direct, yet drop ships air cleaners marketed by merchants.

2. URL


Provides some reservations that the A350 should only be used in smaller rooms.


  • Highlights that this particular purifier can be mounted on the wall
  • States that the replacement filters  are relatively cheap
  • Mentions that the A350 comes with a Lifetime warranty


  • Talks about how come consumers mention that the power supply causes a “humming” sound
  • Indicates that this air purifier should only be used in smaller rooms

CADR Results:

Sadly the A350 has not undergone a CADR test so we can not provide this results for this test. Thankfully Ed at air-purifier-power has worked out that this purifier has a similar ranking to a CADR ranking of 203.

The Alen A350 therefore has an estimated score of: 203 CADR Ranking

Technology Used:


1.HEPA Filter

The Alen A350 uses one combined HEPA, carbon, and pre-filter in one unit. The only issue this raises is the price as the purifier requires this combined filter to be changed every six months. Currently, you can purchase the A350 filters on for $49.99 which is not too bad but bear in mind that you will need to replace these twice each year – so it’s $100 per year. If I compare this with other purifiers that use Lifetime HEPA such as the Honeywell 50250-N, the A350 is considerably more costly to run.

2. Ionizer Function

One of the nice benefits of the Alen A350 is that it comes packaged with an inbuilt non-ozone ionizer unit. Normally I would suggest that people steer clear of ionizer only units but when combined with a strong HEPA filter it can help improve cleaning efficiency. The ionizer unit will charge the surrounding particles with a negative charge which will mean that these particles are heavier and thus picked up more easily by the HEPA filter. Negative ions have also been shown to imbue of sense of well being but this still has not been confirmed by scientific studies. If you are not sure about the ionizer then you can easily disable the function using the on-off switch at the top of the unit.

Power Consumption

The A350 has a Energy Star Rating which should reduce it’s electricity to just pennies per day.

Addressing the Sound Problem

Some reviews have mentioned that the A350 has a whining sound when running. In tests we came across no such noise and believe that this whining sound was down to broken air purifiers. On the highest setting the A350 creates a noise level of 65 dB which is relatively loud. In the video below I show the Alen a350 working at each different sound level so you can evaluate if it’s too loud for your home. 

Whilst the purifier is loud at the level 5 setting, it’s unlikely that you would need to leave it at this level for much time. I am quite happy with the sound output at the lowest level and so would not find a problem sleeping with it running in my bedroom.


This purifier provides a significant amount of cleaning for a small price of just under $400. It can be used in medium-sized rooms (400 square feet recommended) and has the ability to successfully remove all types of particles. My only issue with this purifier relates to the cost of replacement filters ($100 each year) and the lack of VOC capabilities.

When comparing with other purifiers you should make sure that you take into account the $100 a year cost as some Lifetime HEPA filters will work out far cheaper in the long-run and may outweigh the initial extra cost.

The Alen A350 air purifier is currently the highest-rated purifier in my medium range ($200-$700) purifiers and I give it a 5 star rating.

If you want to move away from Alen for your next air purifier, then check out my latest recommendations for the best air purifiers for wildfire smoke.

Last update on 2021-07-29 / Affiliate links / Images from Amazon Product Advertising API